Thanks for answering me !!
The point is that I cant be that relaxed because I dont want my family to discover that I masturbate
For example , if Im taking a shower or peeing or whatever , my sister or my mom come to the bathroom to brush their teeth or wash their hands or something like that ... I dont have any privacy

I understand why you don't want your family to know you masturbat. Can you do i5 in your bed or in your bedroom in general. Why do they not let you in private when you sit on the toilet or you are under the shower. Can you tell them that you like to be alone in the bathroom and that it is embarrassing for you? You could maybe wait for the night when everyone is in bed.